Synthesis of Some New Pyridazin-3-one Derivatives and Their Utility in Heterocyclic Synthesis

Synthesis of new heterocyclic compounds containing the pyridazinone moiety, which have a valuable biological activities, has been achieved through the nucleophilic addition of benzylamine to 4-(p-substituted phenyl)-4-oxo-2-butenoic acid 1a,b, followed by cyclocondensation of the adducts 2a,b to the corresponding pyridazin-3-one derivatives 3a,b. The behavior of the latter compounds toward different nucleophilic and electrophilic reagents was investigated. The structures of the newly synthesized compounds were elucidated by elemental analysis and spectroscopic data.